Organo-Lewis acid as cocatalyst for cationic homogeneous Ziegler-Natta olefin polymerizations

ABSTRACT

Organo-Lewis acids of the formula BR&#39;R&#39;&#39;2 wherein B is boron, R&#39; is fluorinated biphenyl, and R&#39;&#39; is a fluorinated phenyl, fluorinated biphenyl, or fluorinated polycyclic fused ring group, and cationic metallocene complexes formed therewith. Such complexes are useful as polymerization catalysts.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of our prior application Ser.No. 09/220,741, filed Dec. 23, 1998, now U.S. Pat. No. 6,087,460, whichis a division of application Ser. No. 08/800,548, filed Feb. 18, 1997,now U.S. Pat. No. 5,856,256, issued Jan. 5, 1999, which in turn claimspriority of U.S. provisional application No. 60/011,920, filed Feb. 20,1996.

This invention was made with Government support under Contract No.DE-FG02-86ER13511 awarded by the Department of Energy. The Governmenthas certain rights in this invention.

BACKGROUND OF THE INVENTION

This invention relates to the compositions of matter useful ascatalysts, to a method for preparing these catalysts and to a method forpolymerization utilizing the catalysts.

The use of soluble Ziegler-Natta type catalysts in the polymerization ofolefins is well known in the prior art. In general, such systems includea Group IV-B metal compound and a metal or metalloid alkyl cocatalyst,such as aluminum alkyl cocatalyst. More broadly, it may be said toinclude a mixture of a Group I-III metal alkyl and a transition metalcomplex from Group IVB-VB metals, particularly titanium, zirconium, orhafnium with aluminum alkyl cocatalysts.

First generation cocatalyst systems for homogeneous metalloceneZiegler-Natta olefin polymerization, alkylaluminum chlorides (AlR₂Cl),exhibit low ethylene polymerization activity levels and no propylenepolymerization activity. Second generation cocatalyst systems, utilizingmethyl aluminoxane (MAO), raise activities by several orders ofmagnitude. In practice however, a large stoichiometric excess of MAOover catalyst ranging from several hundred to ten thousand must beemployed to have good activities and stereoselectivities. Moreover, ithas not been possible to isolate characterizable metallocene activespecies using MAO. The third generation of cocatalyst, B(C₆F₅)₃, provesto be far more efficient while utilizing a 1:1 catalyst-cocatalystratio. Although active catalyst species generated with B(C₆F₅)₃, areisolable and characterizable, the anion MeB(C₆F₅)₃ ^(⊖), formed afterMe^(⊖) abstraction from metallocene dimethyl complexes is weaklycoordinated to the electron-deficient metal center, thus resulting in adrop of certain catalytic activities. The recently developed B(C₆F₅)₄^(⊖) type of non-coordinating anion exhibits some of the highestreported catalytic activities, but such catalysts have proven difficultto obtain in the pure state due to poor thermal stability and poorcrystallizability, which is crucial for long-lived catalysts and forunderstanding the role of true catalytic species in the catalysis forthe future catalyst design. Synthetically, it also takes two more stepsto prepare such an anion than for the neutral organo-Lewis acid.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the subject invention to prepare andutilize a new class of olefin polymerization catalysts.

A further object of the subject invention is a catalyst which permitsbetter control over molecular weight, molecular distribution,stereoselectivity, and comonomer incorporation.

Another object of the subject invention is a Ziegler-Natta type catalystsystem which reduces the use of excess cocatalyst and activatespreviously unresponsive metallocenes.

These and other objects are attained by the subject invention whereby inone embodiment, a strong organo-Lewis acid, such asperfluorobiphenylborane (PBB) is utilized as a highly efficientcocatalyst for metallocene-mediated olefin polymerization and as acatalyst for a ring opening polymerization of THF. PBB can besynthesized in much higher yield than B(C₆F₅)₃ and the anion generatedwith PBB is non-coordinating instead of weakly coordinating as in thecase of B(C₆F₅)₃. Thus, the former exhibits higher catalytic activitiesand can activate previously unresponsive metallocenes. The catalyticallyactive species generated with PBB are isolable, X-raycrystallographically characterizable instead of the unstable, oilyresidues often resulting in the case of B(C₆F₅)₄ ^(⊖). In addition, PBBexhibits even higher catalytic activities in most cases.

In one embodiment of the subject invention a strong organo-Lewis acid,such as perfluorobiphenylborane (PBB), is utilized to synthesizestoichiometrically precise, isolable/crystallographicallycharacterizable, highly active “cation-like” metallocene polymerizationcatalysts. The biphenyl groups of PBB may be connected to the boron atthe meta, para, or ortho position.

PBB reacts with early transition metal or actinide alkyls to yieldhighly reactive cationic complexes: (CpCp′MR)^(⊕) (RBR′R″₂)^(⊖)

where

CpCp′=C₅H_(n)R_(5−n) (n is 0-5), indenyl, allyl, benzyl,C₅H_(n)R_(4−n)XNR (n is 0-4);

M=early transition metal or actinide, e.g., Ti, Zr, Hf, Th, U;

X=R′″₂Si, where R′″ is an alkyl or aryl group (C≦10);

R, R′″=alkyl, benzyl, or aryl group (C≦20), hydride, silyl;

B=boron

R′=fluorinated biphenyl

R″=fluorinated phenyl, fluorinated biphenyl, or fluorinated polycyclicfused rings such as naphthyl, anthracenyl, or fluorenyl.

As a specific example of the above, the reaction of PBB with a varietyof zirconocene dimethyl complexes proceeds rapidly and quantitatively toyield, after recrystallization from hydrocarbon solvents, the catalyticcomplex of Eq. 1.

Such catalytic complexes have been found to be active homogeneouscatalysts for α-olefin polymerization and, more particularly, thepolymerization, copolymerization or oligopolymerization of ethylene,α-olefins, dienes and acetylenic monomers, as well as intramolecular C—Hactivation.

The cocatalyst of the subject invention may be referred to as BR′R″₂,where B=boron; R′ and R″ represent at least one and maybe morefluorinated biphenyls or other polycyclic groups, such as naphthyl. Twoof the biphenyls may be substituted with a phenyl group. Both thebiphenyls and the phenyl groups should be highly fluorinated, preferablywith only one or two hydrogens on a group, and most preferably, as inPBB with no hydrogens and all fluorines.

BRIEF DESCRIPTION OF THE DRAWINGS

The cocatalyst system of the subject invention can be better understoodwith reference to the drawings wherein:

FIG. 1 is a structural depiction of PBB;

FIG. 2 is a reaction pathway for the synthesis of PBB;

FIG. 3 shows the reaction pathway for a catalyst system according to thesubject invention;

FIG. 4 shows the reaction pathway for a second catalyst system accordingto the subject invention;

FIG. 5 shows the reaction pathway for a third catalyst system accordingto the subject invention;

FIG. 6 shows the reaction pathway for a fourth catalyst system accordingto the subject invention; and

FIG. 7 shows the reaction pathway for a fifth catalyst system accordingto the subject invention.

DETAILED DESCRIPTION OF THE INVENTION

The reaction of perfluorobiphenylborane with a variety of zirconoceneand other actinide or transition metal dimethyl complexes proceedsrapidly and quantitatively at room temperature in noncoordinatingsolvents to yield, after recrystallization, complexes. This catalystactivation reaction may be used in the polymerization, copolymerization,oligomerization and dimerization of α-olefins. In addition, the catalystof the subject invention may be used in conjunction with aluminumalkyls, aluminum aryls, (AlR₃, R=Et, Me, Ph, naphthyl) or methylalumoxane (Al(CH₃)O)_(n) for increased polymer yields.

PBB (FIG. 1) has been synthesized in quantitative yields of 91 % ascompared to the 30-50% yields experienced with B(C₆F₅)₃, currently avery important Lewis acidic cocatalyst in industry (FIG. 2). The Lewisacidity of PBB has been shown to be much greater than that of B(C₆F5)₃by comparative reactions of Cp*₂ThMe₂ with B(C₆F₅)₃ and PBB (Cp*=C₅Me₅).The former reagent does not effect Me^(⊖) abstraction, while the lattergives the catalyst shown in FIG. 3. The reaction of PBB with a bis-Cptype of dimethyl zirconocenes forms a dinuclear methyl-bridgedzirconocene cation such as

(1:1 or 2:1)

where

Cp=C₅H₅

Cp=C₅H₃Me₂ or

Cp=C₅Me₅

and a hydride-bridged analog such as

where

Cp=C₅H₅ or

Cp=C₅H₃Me₂

More particularly, reaction of PBB with group 4 and Th methyls proceedscleanly to yield cationic complexes such as set forth below.

For ethylene polymerization, catalytic activities of dinuclear cationsgenerated from PBB are greater than those of monomeric cations generatedfrom B(C₆F₅)₃ presumably because (MePBB)^(⊖) is a non-coordinating anionas compared to the weakly coordinating anion MeB(C₆F₅)₃. The dinuclearcations have also been found to catalyze the rapid ring-openingpolymerization of THF to produce poly(tetrahydrofuran), an importantthermoplastic elastomer and artificial leather. Monomeric zirconocenecations have also been generated in situ by the reaction of Cp₂ZrMe₂ andPBB at 60° C.:

where Cp=C₅H₅, C₅H₃Me₂, or C₅Me₅, or

These attempts show very high activities for olefin polymerization, andidentify (MePBB)^(⊖) to be a truly non-coordinating anion. Thepolymerization data with metallocene cations having various anions aresummarized in Table 1.

TABLE 1 Polymerization Data Entry μmol Polymer M_(wd) ^(c) No. Catalystof cat Conditions Monomer(s)^(a) yield (g) Activity^(b) (10⁻³)M_(w)/M_(n) Remarks  1 (Cp₂ZrMe)₂Me^(⊕) 15 100 mL toluene ethylene 0.804.80 × 10⁶ 559 3.06 MePBB^(⊖) 25° C., 40 s  2 Cp₂ZrMe^(⊕) 15 100 mLtoluene ethylene 1.00 4.00 × 10⁶ 124 2.03 MeB(C₆F₅)₃ ^(⊖) 25° C., 60 s 3 (CP″₂ZrMe)₂Me^(⊕) 15 100 mL toluene ethylene 1.30 7.80 × 10⁶ 392 2.72MePBB^(⊖) 25° C., 40 s  4 Cp″₂ZrMe^(⊕) 15 100 mL toluene ethylene 1.506.00 × 10⁶ 321 1.42 MeB(C₆F₅)₃ ^(⊖) 25° C., 60 s  5 (Cp*₂ZrMe)₂Me^(⊕) 15100 mL toluene ethylene 1.07 4.30 × 10⁶ 370 2.28 MePBB^(⊖) 25° C., 60 s 6 Cp*₂ZrMe^(⊕) 15 100 mL toluene ethylene 0.80 3.20 × 10⁶ 136 2.54MeB(C₆F₅)₃ ^(⊖) 25° C., 60 s  7 Cp*TiMe^(⊕) ₂ 50 5 mL toluene styrene0.35 1.61 × 10⁶ 170 2.56 [rrrr] > 98% MePBB^(⊖) 25° C., 15 min  8Cp*ZrMe^(⊕) ₂ 50 5 mL toluene styrene 1.45 1.00 × 10⁷ 27.6 2.63 atacticMePBB^(⊖) 25° C., 10 min  9 Cp*HfMe^(⊕) ₂ 50 5 mL toluene styrene 0.693.17 × 10⁶ 24.8 2.98 atactic MeB(C₆F₅)₃ ^(⊖) 25° C., 15 min 10Cp*HfMe^(⊕) ₂ 50 5 mL toluene styrene 1.16 5.33 × 10⁶ 22.9 2.78 atacticMePBB^(⊖) 25° C., 15 min 11 Cp*TiMe^(⊕) ₂ 50 25 mL toluene ethylene 0.701.70 × 10⁵ 848 23.7 39.5% hexene MeB(C₆F₅)₃ ^(⊖) 25° C., 5 min 1-hexeneincorporation 12 Cp*TiMe^(⊕) ₂ 50 25 mL toluene ethylene 4.51 1.08 × 10⁶151 4.32 43.6% hexene MePBB^(⊖) 25° C., 5 min 1-hexene incorporation 13CGCZrMe^(⊕) 15 100 mL toluene ethylene 0 — — — MeB(C₆F₅)₃ ^(⊖) 25° C.,20 min 14 CGCZrMe^(⊕) 15 100 mL toluene ethylene 1.56 1.56 × 10⁶ 7.692.78 MePBB^(⊖) 25° C., 4 min 15 CGCTiMe^(⊕) 15 100 mL toluene ethylene0.21 8.40 × 10⁴ 1058 9.54 MeB(C₆F₅)₃ ^(⊖) 25° C., 10 min 16 CGCTiMe^(⊕)15 100 mL toluene ethylene 0.83 4.98 × 10⁶ 305 2.56 MePBB^(⊖) 25° C., 40s 17 CGCZrMe^(⊕) 50 25 mL toluene ethylene 0 — — — MeB(C₆F₅)₃ ^(⊖) 25°C., 15 min 18 CGCZrMe^(⊕) 50 25 mL toluene ethylene 6.97 5.58 × 10⁵ 10.02.68 33.6% hexene MePBB^(⊖) 25° C., 15 min 1-hexene incorporation 19CGCTiMe^(⊕) 25 25 mL toluene ethylene 0.05 1.20 × 10⁴ 63.2% hexeneMeB(C₆F₅)₃ ^(⊖) 25° C., 10 min 1-hexene incorporation 20 CGCTiMe^(⊕) 2525 mL toluene ethylene 1.95 4.68 × 10⁵ 105 1.86 65.3% hexene MePBB^(⊖)25° C., 10 min 1-hexene incorporation ^(a)1 atm ethylene pressure; 17.4mmol of styrene, & 44.5 mmol of 1-hexene. ^(b)g polymer/[(mol ofcationic metallocene).atm.h], except in entries 7-10: polystyrene/[(molcatalyst).(mol monomer).h] (reproducibility between runs ≈ 10˜15%).^(c)GPC relative to polystyrene standards.

Other types of cationic metallocene catalyst systems can also be createdwith PBB. Metallocene cations of mono-Cp type (FIGS. 4 and 5) have beenformed by the reaction of mono-pentamethyl Cp trimethyl group IVcomplexes with PBB. These are very good syndiospecific styrenepolymerization catalysts. Constrained geometry types of zirconocene andtitanocene cations such as those in FIG. 6 where m=Zr, Ti, are readilyproduced by the reaction of the corresponding dimethyl metallocenes withPBB. They are highly naked cations and much more active catalysts thanthose generated with B(C₆F₅)₃.

EXAMPLE 1

Synthesis of Perfluorobiphenylborane (PBB)

n-Butyllithium (1.6 M in hexanes, 25 mL, 40 mmol) was added dropwise tobromopentafluorobenzene 18.0 g, 9.1 mL, 72.9 mmol) in 100 mL of diethylether over a cold-water bath. The mixture was then stirred for a further12 h at room temperature. Removal of solvent followed by vacuumsublimation at 60-65° C./10⁻⁴ torr gave 12.0 g of2-bromononafluorobiphenyl as a white crystalline solid: yield 83.3%. Thedangerous and explosive nature of C₆F₅Li-ether solutions in thispreparation can be avoided by (a) the use of excess of C₆F₅Br, (b) slowaddition of n-butyllithium, (c) frequent change of the cold water bath,or use of a continuous flowing cold water bath.

To the above prepared 2-bromononafluorobiphenyl (5.0 g, 12.7 mmol) in amixed solvent of 70 mL of diethyl ether and 70 mL of pentane wasgradually added 8.0 mL of n-butyllithium (1.6 M in hexanes, 12.8 mmol)at −78° C. The mixture was stirred for an additional 2 h, and borontrichloride (4.0 mL, 1.0 M in hexanes, 4.0 mmol) was then quickly addedby a syringe. The mixture was left at −78° C. for 1 h and thetemperature was then allowed to slowly rise to room temperature. Asuspension resulted after stirring an additional 12 h. It was filteredto give a yellow solution, and the solvent of the filtrate was removedin vacuo. The resulting pale yellow powder was sublimed at 140° C./10⁻⁴torr or 125° C./10⁻⁶ torr to produce a light yellow crystalline solid asan ether-free crude product. Recrystallization from pentane at −20° C.gave 3.5 g of the pure PBB as a white crystalline solid: yield 91.0%.Analytical and spectroscopic data for PBB are as follows. ¹⁹F NMR (C₆D₆,23° C.): δ−120.08 (s, br, 3 F, F-3), −132.09 (s, br, 3 F, F-6), −137.66(s, br, 6 F, F-2′/F-6′), −143.31 (t, ³J_(F-F)=21.4 Hz, 3 F, F-4),−149.19 (t, ³J_(F-F)=21.7 Hz, 3 F. F-4′), −150.56 (t, ³J_(F-F)=14.7 Hz,3 F, F-5), 160.72 (s, br, 6 F, F-3′/F-5′). ¹³C NMR (C₆D₆, 23° C. ):δ150.92 (dd, ¹J_(C-F)=251.8 Hz, ²J_(C-F)=10.1 Hz, 3 C), 146.35 (dd,¹J_(C-F)=254.3 Hz, ²J_(C-F)=12.1 Hz, 3 C), 144.26 (dd, ¹J_(C-F)=258.1Hz, ²J_(C-F)=10.5 Hz, 6 C), 143.50 (tt, ¹J_(C-F)=265.4 Hz, ²J_(C-F)=12.0Hz, 3 C), 141.98 (tt, ¹J_(C-F)=261.4 Hz, ²J_(C-F)=11.7 Hz, 3 C), 141.17(tt, ¹J_(C-F)=254.3 Hz, ²J_(C-F)=10.5 Hz, 3 C), 137.70 (tt,¹J_(C-F)=257.3 Hz, ²J_(C-F)=11.6 Hz, 6 C), 124.51 (d, ²J_(C-F)=11.7Hz, 3C), 113.60 (d, ²J_(C-F)=11.5 Hz, 3 C), 106.05 (s, br, 3 C). MS: parention at m/e 956. Anal. Calcd for C₃₆BF₂₇: C, 45.22; H, 0.00. Found: C,45.44; H, 0.05.

EXAMPLE 2

Synthesis of Cp*₂ThMe^(⊕) (MePBB)^(⊖)

Cp*₂ThMe₂ (0.106 g, 0.199 mmol) and PBB (0.191 g, 0.199 mmol) were inthe glove box charged into a 25-mL reaction flask with a filter plug,and the flask was attached to the high vacuum line. Benzene (15 mL) wasthen vacuum-transferred into this flask at −78° C. The mixture wasslowly allowed to warm to room temperature and stirred for 6 h. Thesolvent was removed, pentane (20 mL) was next vacuum-transferred intothe flask, and the mixture was filtered after stirring. The white solidwhich collected was dried under vacuum to give 0.210 g of product: yield70.9%. Analytical and spectroscopic data are as follows. ¹H NMR (C₆D₆,23° C.): δ1.61 (s, 30 H, C₅Me₅), 0.62 (s, 3 H, Th—CH₃), −095 (s,br, 3 H,B—CH₃). ¹⁹F NMR (C₆D₆, 23° C.): δ−124.57 (s, br, 3F), −138.10 (s, br, 3F), −139.28 (d, ³J_(F-F)=21.4 Hz, 3 F), −139.74 (d, ³J_(F-F)=21.2 Hz, 3F), −155.08 (t, ³J_(F-F)21.4 Hz, 3 F), −157.32 (t, ³J_(F-F)=22.0 Hz, 3F), −162.20 (t, ³J_(F-F)=22.0 Hz, 3 F), −163.13 (t, ³J_(F-F)=22.0 Hz, 3F), −163.90 (t, ³J_(F-F)=21.4 Hz, 3 F). ¹³C NMR (C₆D₆, 23° C.): δ129.54(C₅Me₅), 79.28 (Th—Me), 10.44 (C₅Me₅), 10.25 (B—Me). Anal. Calcd for C₅₈H₃₆ BF27 Th: C, 46.79; H, 2.44; N, 0.00. Found: C, 46.68; H, 2.24; N.0.00.

EXAMPLE 3

Synthesis of Cp₂Zr(Me)(μ-Me)Me)ZrCp₂ ^(⊕)(MePBB)^(⊖)(Cp=C₅H₅, C₅H₃Me₂,or C₅Me₅

Cp₂ZrMe₂ (0.398 mmol) and PBB (0.199 mmol) were loaded into a 25mL-flask, which was then attached to the vacuum line. Pentane (20 mL)was then vacuum-transferred into this flask at −78° C. The mixture wasslowly warmed to room temperature and stirred for an additional 2 h(Cp=C₅H₅), 15 h (Cp=C₅H₃Me₂) or 48 h (Cp=C₅Me₅). The resultingsuspension was filtered, and the colored solids (light pink for C₅H₅,light yellow for C₅H₃Me₂ and yellow for C₅Me₅) were washed with a smallamount of pentane and dried under vacuum: yields 90.3% (C₅H₅), 86.3%(C₅H₃Me₂) and 34.7% (C₅Me₅). Analytical and spectroscopic data forCP=C₅H₅ are as follows. ¹H NMR (C₆D₆, 23° C.): δ5.65 (s, 20H, C₅H₅),−0.04 (s, 6H, Zr—CH₃), −0.84 (s, br, 3H, B—CH₃), −1.15 (s, 3H,Zr—CH₃—Zr). ¹⁹F NMR (C₆D₆, 23° C.): δ124.20 (d, ³J_(F-)=16.6 Hz, 3 F),−138.98 (d, ³J_(F-F)=20.3 Hz, 3 F), −139.20 (d, ³J_(F-F=)22.0 Hz, 3 F),−140.29 (d, ³J_(F-F)=24.5 Hz, 3 F), −155.15 (t, ³J_(F-F)=20.9 Hz, 3 F),−160.06 (t, ³J_(F-F)=22.3 Hz, 3 F), −162.79 (t, ³J_(F-F)=22.0 Hz, 3 F),−163.11 (t, ³J_(F-F)=21.5 Hz, 3 F), −163.97 (t, ³J_(F-F)=19.0H, 3 F).¹³C NMR (C₆D₆, 23° C.): δ113.24 (C₅H₅), 38.88 (Zr—CH₃), 21.53 (B—CH₃),15.80 (Zr—CH—Zr). Anal. Calcd for C₆₀H₃₂BF₂₇Zr₂: C, 49.39; H, 2.21; N,0.00. Found: C, 48.97; H, 1.92; N 0.00.

Analytical and spectroscopic data for Cp=C₅H₃Me₂ are as follows. ¹H NMR(C₇D₈, 23° C. ): δ5.51 (t, ³J_(H-H)=2.8 Hz, 4H, C₅H₃ Me₂), 5.47(t,³J_(H-H)=3.2 Hz, 4H, C₅H₃Me₂), 5.18 (t, ³J_(H-H)=2.8 Hz, 4H,C₅H₃Me₂), 1.73 (s, 12H, C₅H₃Me₂), 1.51 (s, 12H, C₅H₃MMe₂), −0.26 (s, 6H,Zr—CH₃), −0.92 (s, br, 3H, B—CH₃), −1.50 (s, 3H, Zr—CH₃—Zr). ¹⁹F NMR(C₆D₆, 23° C.): δ123.37 (d, ³J_(F-F)=15.3 Hz, 3F), −139.20 (d,³J_(F-F)=24.0 Hz, 3 F), −139.62 (d, ³J_(F-F)=24.3 Hz, 3 F), −139.89(d,³J_(F-F)=24.0 Hz, 3 F), −155.81 (t, ³J_(F-F)=2.14 Hz, 3 F), −159.36(t, ³J_(F-F)=22.3 Hz, 3 F), −163.22 (t, ³J_(F-F)=21.4 Hz, 3 F), −16.55(t, ³J_(F-F)=22.0 Hz, 3 F), −164.20 (t, ³J_(F-F)=22.6 Hz, 3 F). ¹³C NMR(C₆D₆, 23° C.): δ114.20 (d, ¹J_(CH)=17.1 Hz, C₅H₃Me₂), 113.62 (s,C₅H₃Me₂), 112.80 (s, C₅H₃Me₂), 111.29 (d, ¹J_(CH)165.7 Hz, C₅H₃Me₂),106.57 (d, ¹J_(CH)=173.3 Hz. C₅H₃Me₂), 41.63 (q, ¹J_(C-H)118.4Hz,Zr—CH₃), 31.26 (q, ¹J_(CH)=116.5 Hz, B—CH₃), 22.21 (q, ¹J_(CH)=134.3 Hz,Zr—CH₃—Zr), 12.94 (q, ¹J_(CH)=128.0 Hz, C₅H₂Me₂), 12.71 (q,¹J_(CH)=127.6 Hz. C₅H₂Me₂). Anal. Calcd for C₆₈H₄₈BF₂₇Z₂: C, 51,98; H,3.08; N, 0.00. Found: C, 51.61; H, 3.00; N, 0.00.

Analytical and spectroscopic data for Cp=C₅Me₅ are as follows. ¹H NMR(C₆D₆, 23° C.): δ1.57 (s, 60H, C₅Me₅) −0.84 (s, br, 3H, B—CH₃). Thebridging a terminal methyl groups are discrete at low temperature. ¹HNMR (C₇D₈, −13° C.): δ−0.19 (s, br, 6H. Zr—CH₃), −0.92 (s, br, 3H,B—CH₃), −2.42 (s, br, 3H, Zr—CH₃—Zr). ¹⁹F NMR (C₆D₆, 23° C.): δ−123.11(d, s, br, 3 F), −139.27 (d, ³J_(F-F)=20.3 Hz, 3 F), −139.67 (t,3J_(F-F)=25.1 Hz, 6F), −155.73 (t, ³J_(F-F)=20.9 Hz, 3 F), −160.91 (s,br, 3 F), −163.25 (t, ³J_(F-F)=21.7 Hz, 3 F), −163.56 (t, ³J_(F-F)=22.0Hz, 3 F), −164.13 (t, ³J_(F-F)=21.4 Hz, 3 F). Anal. Calcd forC₈₀H₇₂BF₂₇Zr₂: C, 55.23; H, 4.17; N, 0.00. Found: C, 54.81; H, 3.98; N,0.00.

EXAMPLE 4

Synthesis of Cp₂Zr(H)(μ-H)(H)ZrCp₂ ^(⊕)(MePBB)^(⊖); Cp=C₅H, C₅H₃Me₂

The procedure here is similar to that of Example 3, except that thereaction was carried out under 1 atm of H₂ for 15 h: yields 81.6%(Cp=C₅H₅, grey solid) and 75.6% (Cp=C₅H₃Me₂, orange solid). Analyticaland spectroscopic data for Cp=C₅H₅ are as follows. ¹H NMR (C₆D₆, 58°C.): δ6.67 (s, br, 2H, Zr—H), 5.64 (s, 20H, C₅H₅), −0.81 (s, br, 3H,B—CH₃), −1.38 (s, br, 1H, Zr—H—Zr). The chemical shifts and splittingpatterns of ¹⁹F NMR are same as those of Example 3 (Cp=C₅H₅). Anal.Calcd for C₅₇H₂₆BF₂₇Zr₂: C, 48.31; H, 1.85; N, 0.00. Found: C, 47.90; H,1.92; N, 0.00.

Analytical and spectroscopic data for Cp=C₅H₃Me₂ are as follows. ¹H NMR(C₇D₈, 23° C.): δ5.81 (m, 4H, C₅H₃Me₂), 5.50 (m, 4H, C₅H₃Me₂), 523 (m,4H, C₅H₃Me₂). 1.65 (m, 24H, C₅H₃Me₂), 0.25 (s, br, 2H, Zr—H), −0.94 (s,br, 3H, B—CH₃), −1.52 (s, br, 1H, Zr—H—Zr). The chemical shifts andsplitting patterns of ¹⁹F NMR are same as those of Example 3(Cp=C₅H₃Me₂). Anal. Calcd for C₆₅H₄₂BF₂₇Zr₂: C, 51.05; H, 2.77; N, 0.00.Found C, 51.07; H. −2.63; N. 0.00.

EXAMPLE 5

Preparation of Cp₂ZrMe^(⊕)(MePBB)^(⊖)

5(a) Cp=C₅H₅. In a J-Young NMR tube, a small amount of a mixture ofCp₂ZrMe₂ and PBB (1:1.2 molar ratio) was dissolved in C₆D₆). The NMRtube was then put in an NMR probe and heated at 60° C. After 0.5 h, ¹HNMR revealed the above monomeric species formed. The same structureswere obtained by the reaction of the product of Example 3 with excess ofPBB at 60° C. for 0.5 h. In a real polymerization test, these specieswere also generated in situ by mixing Cp₂ZrMe₂ and PBB at 60° C. for 0.5h. ¹H NMR (C₆D₆, 60° C.) for: δ5.70 (s, 10H, C₅H₅), 0.14 (s, 3H,Zr—CH₃), −0.85 (s, br, 3H, B—CH₃). The ¹⁹F NMR is similar to that of thecorresponding dinuclear species of Example 3 (Cp=C₅H₅).

5(b) Cp=C₅H₃Me₂. The same procedure of Example 5(a) was used to preparethis species. In the polymerization test, the following was observed: ¹HNMR (C₇D₈, 60° C. ) for 8; δ5.68 (t, 3 J H—H=2.8 Hz, 4H, C₅H₃Me₂), 1.76(s, ³J_(H-H)=3.1 Hz, 4H, C₅H₃Me₂), 5.23 (t, ³J_(H-H)=2.8 Hz, 4H,C₅H₃Me₂), 1.76 (s, 6H, C₅H₃Me₂), 1.56 (s, 6H, C₅H₃Me₂), 0.17 (s, 3H,Zr—CH₃), −0.93 (s, br, 3H, B—CH₃). ¹⁹F NMR of this species is similar tothat of the corresponding dinuclear species of Example 3 (Cp=C₅Me₅). ¹³CNMR (C₇D₈, 60° C. ): δ117.74 (C₅H₃Me₂), 112.14 (C₅H₃Me₂), 108.01(C₅H₃Me₂), 42.11 (Zr—CH₃), 34.43 (B—CH₃), 12.63 (C₅H₂Me₂), 12.45(C₅H₂Me₂).

5(c) Cp=C₅Me₅ The same procedure of Example 5(a) was used to preparethis species. In the polymerization test, the following was observed: ¹HNMR (C₆D₆, 60° C.): δ1.61 (s, 30H, C₅Me₅), 0.13 (s, 3H, Zr—CH₃), −0.86(s, br, 3H, B—CH₃). ¹⁹F NMR is similar to that of the correspondingdinuclear species of Example 3, Cp=C₅Me₅.

EXAMPLE 6

Synthesis of CpM(Me)₂ ^(⊕)(MePBB)^(⊖); Cp=C₅Me₅

M=Ti. The catalyst product of FIG. 5 was generated in the NMR tubereaction by mixing C₅Me₅TiMe₃ and PBB at 1:1 molar ratio in C₆D₆ for 2h. ¹H NMR (C₆D₆, 23° C.): δ9.03 (s, br, 2H, CH₂), 1.69 (s, 6H, C₅Me₄),1.65 (s, 6H, C₅Me₄), 0.15 (s, 3H, Ti—CH₃), −0.82 (s, br, 3H, B—CH₃).

EXAMPLE 7

Synthesis of Me₂Si(^(t)BuN)(C₅Me₄)MMe^(⊕)(MePBB)^(⊖)

M=Zr. Me₂Si(^(t)BuN)(C₅Me₄)MMe₂ (0.199 mmol) and PBB (0.199 mmol) weretreated in the same manner as in the preparation of Example 2 except forthe different reaction times (2 h). This procedure yields 73.1% (yellowsolid). Analytical and spectroscopic data are as follows. ¹H NMR (C₇D₈,23° C.): δ1.73 (s, 3H, C₅Me₄), 1.69 (s, 3H, (C₅Me₄), 1.63 (s, 3H,C₅Me₄), 1.43 (s, 3H, C₅Me₄), 0.85 (s, 9H, N-^(t)Bu), 0.28 (s, 3H,SiMe₂), 0.21 (s, 3H, SiMe₂), −0.48 (s, 3H, Zr—CH₃), −0.95 (s, br, 3H,B—CH₃). ¹⁹F NMR (C₇D₈, 23° C.): δ124.20 (s, br, 3 F), −139.14 (d,³J_(F-F)=23.7 Hz, 3 F), −139.35 (d, ³J_(F-F)=22.0 Hz, 3 F), −139.93 (d,³J_(F-F)=21.2 Hz, 3 F), −155.79 (t, ³J_(F-F)=21.2 Hz, 3 F), −159.67 (t,³J_(F-F)=22.3 Hz, 3 F), −163.28 (t, ³J_(F-F)=21.7 Hz, 3 F), −163.87 (t,³J_(F-F)=22.6 Hz, 3 F), −164.13 (t, ³J_(F-F)=22.6 Hz, 3 F). ¹³C NMR(C₇D₈, 23° C.): δ130.22 (C₅Me₄), 128.18 (C₅Me₄), 127.22 (C₅Me₄), 126.47(C₅Me₄), 124.37 (C₅Me₄), 58.47 (N—CMe₃), 34.37 (Zr—CH₃), 34.10 (N—CMe₃),15.89 (C₅Me₄), 13.46 (C₅Me₄), 11.77 (C₅Me₄), 10.99(C₅Me₄), 7.92 (SiMe₂),5.65 (SiMe₂). Anal. Calcd for C₅₃H₃₃BF₂₇NSiZr: C, 47.97; H, 2.51; N,1.06, Found: C, 47.79; H, 2.58; N, 0.86.

EXAMPLE 8

Ethylene Polymerization

The reaction was conducted in a 250 mL flamed round bottom flaskattached to a high vacuum line. The flask was equipped with a largemagnetic stirring bar and a straight-bore high vacuum stopcock. Theexterior connecting tube of the stopcock (Ca. 10 mm in length) is sealedwith a new serum cap. The reaction vessel is then evacuated for severalhours, back-filled with inert gas (Ar), the stopcock closed, and thereaction flask reevacuated. A measured amount of a nonpolar solvent suchas benzene or toluene is vacuum transferred into the flask. Gaseousethylene is admitted to the reaction flask through the purificationcolumn. The gas pressure is continuously maintained at 1 atm. Rapidstirring of the solution is initiated and after several minutes (toallow the saturation of the solvent with ethylene), the stopcock isopened and a small aliquot of catalyst solution (in the same solvent asused for the reaction) is injected by a gas-tight syringe just above therapidly stirring solution through a serum cap (the syringe needle hadbeen flattened so that the catalyst solution exits in a fine spray).Solid polyethylene is formed immediately. The reaction is quenched aftera certain amount of time by injecting methanol through the serum cap onthe stopcock. The solid polyethylene was collected by filtration, washedwith methanol and then dried under vacuum at 100° C. Copolymerizationmay occur with the addition of a second monomer such as anotherα-olefin.

Ethylene polymerizations were carried out at room temperature in 250-mLflamed, round-bottom flasks attached to a high-vacuum line. In a typicalexperiment, a solution of each of the catalysts of Example 3 in 2 mL oftoluene was quickly injected using a gas-tight syringe equipped with aspraying needle into respective rapidly stirred flasks containing 100 mLof toluene which was pre-saturated under 1 atm of rigorously purifiedethylene. In the case of the catalysts prepared in Example 3, thecatalyst solution was generated in situ by mixing Cp₂ZrMe₂ and PBB in 2mL of toluene after aging for 0.5 h at 60° C., and then quickly injectedinto respective flasks under an ethylene atmosphere using a pre-warmedgas-tight syringe. The polymerization was quenched with acidic CH₃OHafter a short time period (10-60 s) at which point voluminous quantitiesof polyethylene precipitated out. The respective polymeric products werecollected by filtration, washed with methanol and dried under highvacuum to a constant weight.

EXAMPLE 9

Ring-Opening Polymerization of THF

A small amount of [(C₅H₃Me₂)₂(Me)Zr—Me—Zr(Me)(C₅H₃Me₂)₂]^(⊕) (MePBB)^(⊖)was loaded into a J-Young NMR tube and THF-d₈ was thenvacuum-transferred into the tube. The mixture was slowly warmed to roomtemperature and left for several hours. The solid polymer formed in thetube was shown to be polytetrahydrofuran by ¹H analysis.

EXAMPLE 10

Propylene Polymerization

This reaction is carried out in a 100 mL quartz Worden vessel equippedwith a magnetic stirring bar, a pressure gauge and a stainless steelo-ring assembly attached to a high vacuum line. In a typical experiment,the reaction vessel is flamed and then pumped under high vacuum forseveral hours, filled with inert gas and brought into a glove box. Ameasured amount of catalyst is added into the vessel. On the high vacuumline, a measured amount of the solvent and propylene are condensed in at−78° C. The reaction apparatus is sealed off and warmed to the desiredtemperature. During the polymerization process, the reaction tube isimmersed in a large amount of tap water (20-25° C.) or ice water (0° C.)to help dissipate the heat produced from the polymerization and keep thetemperature constant. The progress of the polymerization reactions ismonitored through observance of the pressure change. After the reactionis finished (pressure drops to zero psi), the resulting oily liquid isremoved from the vessel, washed with methanol and water and dried undervacuum at 90-100° C. for ten hours to result in a colorless oil.

Table II sets forth the relevant data concerning propylenepolymerization utilizing the catalyst prepared according to theenumerated example.

TABLE II Example 3 5 Metallocene (Cp₂ZrMe)₂Me^(⊕)/(Cp₂ZrMe^(⊕))/(MePBB)^(⊖) Cation/Anion* (MePBB)^(⊖) Catalyst (mM) 0.150.15 Reaction Time (m) 40 40 Yield (g) 4.0 5.0 *Cp = C₅H₅

While the invention has been described with reference to a preferredembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention, but that the inventionwill include all embodiments and equivalents falling within the scope ofthe appended claims.

Various features of the invention are set forth in the following claims.

That which is claimed is:
 1. A catalytic complex selected from the groupconsisting of: A) a complex of the formula[CpCp′MMe(μ-Me)MeMCpCp′]^(⊕)[MeBR′R″₂]^(⊖) B) a complex of the formula[CpCp′MH(μ-H)HMCpCp′]^(⊕)[MeBR′R″₂]^(⊖) C) a complex of the formula[CpMMe₂]^(⊕)[MeBR′R″₂]^(⊖) D) a complex of the formula[C₅H_(m)R_(4−m)XNRMMe]^(⊕)[MeBR′R″₂]^(⊖) E) a complex of the formula[CpCp′MMe]^(⊕)[MeBR′R″₂]^(⊖) where: Cp and Cp′ each is C₅H_(n)R_(5−n)where n is 0-5, or indenyl; R is an alkyl or benzyl or aryl or silylgroup, each having 20 or less carbon atoms; M is Th, Zr, Hf, or Ti; Meis methyl; B is boron; H is hydrogen; R′ is fluorinated biphenyl; R″ isa fluorinated phenyl, fluorinated biphenyl, or fluorinated polycyclicfused ring group; m is 0-4; X is R′″₂Si, R′″ being alkyl or aryl, eitherone having 10 or less carbon atoms; and N is nitrogen.
 2. A catalyticcomplex of claim 1 of the formula[CpCp′MMe(μ-Me)MeMCpCp′]^(⊕)[MeBR′R″₂]^(⊖) where each of Cp and Cp′ isC₅H_(n)R_(5−n) and n is 0-5; R is alkyl or benzyl or aryl, each of 20 orless carbon atoms; M is Th, Zr, Hf, or Ti; Me is methyl; B is boron; R′is fluorinated biphenyl; and R″ is a fluorinated phenyl, fluorinatedbiphenyl, or fluorinated polycyclic fused ring group.
 3. A complex ofclaim 2 wherein each R″ is fluorinated biphenyl.
 4. A complex of claim 2wherein R′ is nonafluorobiphenyl, and wherein each R″ isnonafluorobiphenyl.
 5. A complex of claim 3 wherein each of Cp and Cp′is η⁵-cyclopentadienyl, η⁵-dimethylcyclopentadienyl, or⁵-pentamethylcyclopentadienyl.
 6. A complex of claim 4 of the formula[(η⁵-C₅H₅)₂ZrMe(μ-Me)MeZr(η⁵-C₅H₅)₂]^(⊕)[MePBB]^(⊖).
 7. A complex ofclaim 4 of the formula[η⁵-1,2-Me₂C₅H₃)₂ZrMe(μ-Me)MeZr(η⁵-1,2-Me₂C₅H₃)₂]^(⊕)[MePBB]^(⊖).
 8. Acomplex of claim 4 of the formula[(η⁵-Me₅C₅)₂ZrMe(μMe)MeZr(η⁵-Me₅C₅)₂]^(⊕)[MePBB]^(⊕).
 9. A catalyticcomplex of claim 1 of the formula[CpCp′MH(μ-H)HMCpCp′]^(⊕)[MeBR′R″₂]^(⊖) where each of Cp and Cp′ isC₅H_(n)R_(5−n) and n is 0-5; R is alkyl or benzyl or aryl, each of 20 orless carbon atoms; M is a Th, Zr, Hf, or Ti; H is a hydrogen atom; B isboron; R′ is fluorinated biphenyl; and R″ is a fluorinated phenyl,fluorinated biphenyl, or fluorinated polycyclic fused ring group.
 10. Acomplex of claim 9 wherein each R″ is fluorinated biphenyl.
 11. Acomplex of claim 9 wherein R′ is nonafluorobiphenyl, and wherein each R″is nonafluorobiphenyl.
 12. A complex of claim 11 wherein each of Cp andCp′ is η⁵-cyclopentadienyl or η⁵-dimethylcyclopentadienyl.
 13. A complexof claim 11 of the formula[η⁵-C₅H₅)₂ZrH(μ-H)HZr(η⁵-C₅H₅)₂]^(⊕)[MePBB]^(⊖).
 14. A complex of claim11 of the formula[(η⁵-1,2-Me₂C₅H₃)₂ZrH(μ-H)HZr(η⁵-1,2-Me₂C₅H₃)₂]^(⊕)[MePBB]^(⊖).
 15. Acatalytic complex of claim 1 of the formula [CpMMe₂]^(⊕)[MeBR′R″₂]^(⊖)where Cp is C₅H_(n)R_(5−n) and n is 0-5; R is alkyl, benzyl or aryl,each of 20 or less carbon atoms; M is Th, Zr, Hf, or Ti; Me is methyl; Bis boron; R′ is fluorinated biphenyl; and R″ is a fluorinated phenyl,fluorinated biphenyl, or fluorinated polycyclic fused ring group.
 16. Acomplex of claim 15 wherein each R″ is fluorinated biphenyl.
 17. Acomplex of claim 15 wherein R′ is nonafluorobiphenyl, and wherein eachR″ is nonafluorobiphenyl.
 18. A complex of claim 16 wherein Cp isη⁵-cyclopentadienyl, η⁵-dimethylcyclopentadienyl, orη⁵-pentamethylcyclopentadienyl.
 19. A complex of claim 17 of the formula[(η⁵-C₅H₅)TiMe₂]^(⊕)[MePBB]^(⊖).
 20. A complex of claim 17 of theformula [(η⁵-C₅H₅)ZrMe₂]^(⊕)[MePBB]^(⊖).
 21. A complex of claim 17 ofthe formula [(η⁵-C₅H₅)HfMe₂]^(⊕)[MePBB]⁶³ .
 22. A complex of claim 17 ofthe formula [(η⁵-Me₂C₅H₃)HfMe₂]^(⊕)[MePBB]^(⊖).
 23. A complex of claim17 of the formula [(η⁵-Me₂C₅H₃)TiMe₂]^(⊕)[MePBB]^(⊖).
 24. A complex ofclaim 17 of the formula [(η⁵-Me₅C₅)ZrMe₂]^(⊕)[MePBB]^(⊖).
 25. A complexof claim 17 of the formula [(η⁵-Me₅C₅)HfMe₂]^(⊕)[MePBB]^(⊖).
 26. Acatalytic complex of claim 1 of the formula[C₅H_(m)R_(4−m)XNRMMe]^(⊕)[MeBR′R″₂]^(⊖) where m is 0-4; R is alkyl,benzyl or aryl, each of 20 or less carbon atoms; X is R′″₂Si, R′″ beingalkyl or aryl, either one having 10 or less carbon atoms; M is Th, Zr,Hf, or Ti; N is nitrogen; Me is methyl; B is boron; R′ is fluorinatedbiphenyl; and R″ is a fluorinated phenyl, fluorinated biphenyl, orfluorinated polycyclic fused ring group.
 27. A complex of claim 26wherein each R″ is fluorinated biphenyl.
 28. A complex of claim 26wherein R′ is nonafluorobiphenyl, and wherein each R″ isnonafluorobiphenyl.
 29. A complex of claim 26 wherein M is Zr.
 30. Acomplex of claim 26 wherein M is Ti.
 31. A complex of claim 26 of theformula [Me₂Si(^(t)BuN)(C₅Me₄)ZrMe]^(⊕)[MeBR′R″₂]^(⊖)
 32. A complex ofclaim 26 of the formula [Me₂Si(^(t)BuN)(C₅Me₄)TiMe]^(⊕)[MeBR′R″₂]^(⊖)33. A catalytic complex of claim 1 of the formula[CpCp′MMe]^(⊕)[MeBR′R″₂]^(⊖) where each of Cp and Cp′ is C₅H_(n)R_(5−n)is 0-5, or indenyl; R is alkyl or benzyl or aryl, each of 20 or lesscarbon atoms; M is Th, Zr, Hf, or Ti; Me is methyl; B is boron; R′ isfluorinated biphenyl; and R″ is a fluorinated phenyl, fluorinatedbiphenyl, or fluorinated polycyclic fused ring group.
 34. A complex ofclaim 33 wherein each R″ is fluorinated biphenyl.
 35. A complex of claim33 wherein R′ is nonafluorobiphenyl, and wherein each R″ isnonafluorobiphenyl.
 36. A complex of claim 33 wherein each of Cp and Cp′is η⁵-cyclopentadienyl or η⁵-dimethylcyclopentadienyl orη⁵-pentamethylcyclopentadienyl.
 37. A complex of claim 33 of the formula[(η⁵-C₅H₅)₂ZrMe]^(⊕)[MePBB]^(⊖).
 38. A complex of claim 33 of theformula [(η⁵-1,2-Me₂C₅H₃)₂ZrMe]^(⊕)[MePBB]^(⊖).
 39. A complex of claim33 of the formula [(η⁵-Me₅C₅)₂ZrMe]^(⊕)[MePBB]^(⊖).
 40. A complex ofclaim 33 of the formula [(η⁵-Me₅C₅)₂ThMe]^(⊕)[MePBB]^(⊖).